1. Field of the Invention
The invention relates to a torque-transmitting, variably-flexible insertion device. The invention also relates to a method for transmitting torque and variably flexing an insertion device.
2. Description of the Related Art
Insertion devices for surgical instruments are known in the art. Such devices include those which can transition between a relatively stiff and a relatively flexible condition, such as that disclosed in co-pending U.S. patent application Ser. No. 11/367,607, filed Mar. 2, 2006 and naming the inventors of the instant application.
A disadvantage of such variably flexing insertion devices is that the device twists when applying torque to the proximal end and therefore the torque is not transmitted along the device toward the distal end. This makes it difficult or impossible to impart a circumferential movement along the device when needed to traverse the body.